/*
Copyright (c) 2008, Oleg S. Estekhin
All rights reserved.

Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions are met:

    * Redistributions of source code must retain the above copyright notice,
      this list of conditions and the following disclaimer.
    * Redistributions in binary form must reproduce the above copyright notice,
      this list of conditions and the following disclaimer in the documentation
      and/or other materials provided with the distribution.
    * Neither the name of the copyright holders nor the names of its
      contributors may be used to endorse or promote products derived from this
      software without specific prior written permission.

THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR
ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
(INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

package ebml.io;

import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.io.InputStream;

/** The file input source. */
public class FileInputSource implements InputSource {

    private final InputStream in;

    private long position;


    /**
     * Creates a new <code>FileInputSource</code> object.
     *
     * @param fileName the system-dependent name of the file to be opened for reading
     *
     * @throws FileNotFoundException if the file does not exist, is a directory rather than a regular file, or for some
     * other reason cannot be opened for reading
     */
    public FileInputSource(String fileName) throws FileNotFoundException {
        in = new FileInputStream(fileName);
    }

    /**
     * Creates a new <code>FileInputSource</code> object.
     *
     * @param file the file to be opened for reading
     *
     * @throws FileNotFoundException if the file does not exist, is a directory rather than a regular file, or for some
     * other reason cannot be opened for reading
     */
    public FileInputSource(File file) throws FileNotFoundException {
        in = new FileInputStream(file);
    }


    @Override
    public int read(byte[] buffer, int offset, int length) throws IOException {
        int r = in.read(buffer, offset, length);
        if (r < 0) {
            return -1;
        } else {
            position += r;
            return r;
        }
    }

    @Override
    public long skip(long length) throws IOException {
        long r = in.skip(length);
        position += r;
        return r;
    }

    @Override
    public long getPosition() {
        return position;
    }

    @Override
    public void close() throws IOException {
        in.close();
    }

}
